Natural selection was Darwin’s brilliant hypothesis, independently conceived by Wallace, that accounts for adaptations, features that appear “designed” to fit organisms to their environment.

TLS Online TPP Program

#Id: 1547

#Unit 2. Cellular Organization

Taxol, 

A plant alkaloid from the Pacific yew tree

Binds microtubules and stabilizes them against depolymerization

TLS Online TPP Program

#Id: 1548

#Unit 2. Cellular Organization

Nocodazole and colchicine

TLS Online TPP Program

#Id: 1549

#Unit 2. Cellular Organization

Two main families of motor proteins mediate transport along microtubules:

Kinesins 

Dyneins

TLS Online TPP Program

#Id: 1550

#Unit 2. Cellular Organization

Kinesin-1 powers anterograde transport of vesicles down axons toward the (+) ends of microtubules.

TLS Online TPP Program

#Id: 1551

#Unit 2. Cellular Organization

Kinesin-1  (similar to myosin II)

Head domain at the N-terminus of the heavy chain  

Stalk domain forms a long coiled-coil

Tail domain at C-terminus that attaches to cargo

TLS Online TPP Program

#Id: 1552

#Unit 2. Cellular Organization

Kinesin-5 forms tetramers, assembled in a bipolar configuration to interact with two antiparallel microtubules and move toward the (+) ends.